Cell preparation methods influence Escherichia coli D21g surface chemistry and transport in saturated sand.
The effect of cell preparation methods on the surface chemistry and retention of Escherichia coli D21 g was investigated over a range of ionic strength conditions. The cell preparation methods that were considered included filtration and centrifugation (at various speeds and for different durations). For a given ionic strength condition, it was found that cells prepared by filtration were more negatively charged and hydrophobic than cells prepared by centrifugation. Increasing the centrifugation speed (force imposed) or duration produced cells with a higher zeta potential (less negative) and a lower hydrophobicity. Column transport experiments for E. coli D21 g were also conducted with ultra pure quartz sand and the same solution chemistries. The first-order retention rate coefficient for E. coli D21 g increased with increasing speed and duration of centrifugation, and was lowest in the case of filtered cells. Moreover, the influence of cell preparation method was more pronounced in lower ionic strength solutions.
Tazehkand
Shiva S
SS
Dep. of Earth Sciences, Utrecht Univ., Utrecht, the Netherlands.
Torkzaban
Saeed
S
Bradford
Scott A
SA
Walker
Sharon L
SL
D001431:Bacteriological Techniques; D002498:Centrifugation; D004926:Escherichia coli / Q000737:chemistry* / Q000166:cytology*; D005374:Filtration; D012822:Silicon Dioxide; D012988:Soil Microbiology; D014867:Water
D014867:Water; D012822:Silicon Dioxide